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garage door insulation - reflectix ?

todd197555's Avatar

Join Date: Jan 2010
Posts: 1

01-28-10, 07:22 AM   #1  
garage door insulation - reflectix ?

I am new to the site and am thinking about insulating my garage door. It's a uninsulated, steel, 2 car door. I was wondering if Reflectix is good for this. It seems it's R-Value is only 3, though.

Is the foam paneling a better option, or am I better off just insulating the attic space above my garage, which has nothing currently.


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kindest's Avatar

Join Date: Jan 2010
Posts: 11

01-29-10, 11:37 PM   #2  
im 1/2 way done with stapling reflectix underside my roof and plan on doing the garage door last. for me and my location it makes sense (CA). not sure about Ohio but if the garage door takes a beating from the sun then id definately go reflectix but if its more of a heat escaping then id go with the foam.
whats more important keeping it cooler in the summer or warmer in the winter i guess

GregH's Avatar
Super Moderator

Join Date: Jan 2001
Posts: 9,607

01-30-10, 06:19 AM   #3  
The highest heat rejection product by far is insulation, not radiant barrier.
You would do well to first address the lack of insulation and vapor barrier in the ceiling space.

Keep in mind that a radiant barrier surface stuck on a thin layer of foam is not fire rated and could go against fire codes if you install it on interior surfaces.
The same goes for exposed foam board on garage doors.

There is no cheap solution for uninsulated garage doors that doesn't risk house insurance problems.

Radiant barrier has been beaten to death in these forums.
Here are 200 previous threads on the subject.

GregH.........HVAC/R Tech

swat49833's Avatar

Join Date: Feb 2010
Posts: 3

02-15-10, 06:46 AM   #4  
garage insulation

Heres what I have done. Sprayed in radiant barrier on attic ceiling, and yes it works just as good as the RB panels but is alot easier to install. I also blew in 10" of cellulose and floored attic above garage. I then installed regular 2x4 wall insulation on my interior garage door, slightly compressed (only to clear my safety sensors-about 1/2" of compression), then I installed a white pc of form board sandwiched between fiberglass/plastic @ about 1/8 inch total thickness. These close-out panels made a very clean close-out and helped protect the bat insulation, and yes the material is fire retardant. Total R factor is somewhere between R13-R15. Bats are R-13 rating, and the fiber board is about R1. Now since I brought the close out panels home from work, I only have $35.00 total for my 3 car garage... YES 35.00. Garage kits are out there but they are 68.00 per kit, and i would need 3 kits as they only cover a single car garage per kit. That would be about 210.00. Garage stays a 50 degrees while overnight temps have been 32 degrees or less for the past 3 nights in a row.

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